Duplex escapement in watches



0. EL DES COMBES.

' Watch Escapement Patented April 30, 18.40.

UNITED STATES PATENT OFFICE.

E. JAGOT DES COMBES, OF BALTIMORE, MARYLAND.

DUPLEX ESCAPEMENT IN WATCHES.

Specification of Letters Patent No. 1,570, dated April 30, 1840.

To all whom, it may concern Be it known that I, EDWARD JACOT DES GOMBES,of the city of Baltimore, in the State of Maryland, have inventedcertain new and useful improvements in watches and other timekeepers,consisting of a new and improved mode of constructing the escapement,called by me the American cluplex escapement, and also of an improvedmode rendering the movement of the seconds independent; and I do herebydeclare that the following is a full and exact description thereof.

In all. the particulars the movement does not differ from those inordinary use.

In the accompanying drawings I have represented the respective partsshown on a scale enlarged much beyond the actual size, for the purposeof clear description.

Figures 1 and 2 show the arrangement of the parts constituting theescapement; Fig. 3, is a diagram intended to illustrate its action; andF at and 5 show the arrangement of the double train dead seconds, asconstructed on my improved principle.

In Figs. 1, and 2, It, R, represents an escapement wheel moving in thedirection E, F, under the force of the mainspring, in the same way withany other escapement. Upon this wheel there are six arms D, D, each ofwhich terminates in two small teeth (Z, (Z, which cause the escapementto rest by their engaging in the small notch 5, upon the rouleau, orenlargement r, upon the pivot of the balance wheel, which is representedin dotted lines, because it is situated below the piece L. The smallteeth (Z, (Z, enter and escape from the notch s, successively; thesecond tooth escapes at the fourth vibration of the balance wheel, itssituation at this time being that shown at A, Fig. 1. The pin Z, beingone of six on the escapement wheel, then comes into contact with thelever, or tail piece L, and gives the impulse to the balance wheelnecessary to produce the required four vibrations, which must take placein order to mark the time of the seconds, by the striking of the pin Z,on the tail piece L.

In my first experiment I placed the pinion which engages into theseconds wheel, upon the escapement wheel which produced considerablefriction upon the rouleau r, the motive force communicated by the mainspring, pressing with its whole power upon The escapement when so madewas a very good one, operating with great regularity, as experiencefully oroved. But hav- 111g discovered a mode of diminishing thepressure upon the rouleau, to the extent of nearly two thirds, withoutany diminution of the propulsion power on the lever L, its value hasbeen thereby much enhanced. Instead of placing the pinion on the wheelR, I now place it on the wheel G, which has its motion in the directionH, I. The effect of this arrangement will be illustrated by consultingthe diagram Fig. 3. Suppose two radii, A a, B Z), having motion in thecircles C, D, the radius B Z), giving motion to that marked A a; whenthey are parallel to each other the force B, is the greatest, and theforce A, the least; but as they move in the direction E, F, the forcediminishes and the resistance increases, until having arrived at thepoint G, the angle formed by them is a right angle, and the force B Z),is balanced by the resistance A a. The force being the greatest when thetwo radii are parallel, and being reduced to naught when they form aright angle; from this it necessarily follows that the force must fromthis cause be undergoing a gradual diminution while it is appoachingthis angle. From this illustration it will readily be perceived that theforce which presses from the wheel G, upon the pin Z Fig. 2, isdiminished to the extent of two thirds, or nearly so, the two radiibeing of the same length, and forming an angle of 120, or 30 degrees atthe point 1 where the force will be naught, if the axis of the wheel Gis placed there; or adding the angle 0, P, which measures nearly 25 andthe. angle 0 9, (Fig. 2,) which measures 30 total which taken from 90leaves 35/00 of the primitive force as that which presses on therouleau. Vith a. wheel R, R, having six arms, and two teeth upon eacharm, 14,400 vibrations per hour are obtained; and if each of the sixarms carries three teeth, there will be 21,600 vibrations, the principleof action being the same in both cases, four vibrations in a second withtwo teeth, and six vibrations with three teeth.

My new and simple mode of constructing the double train dead seconds isshown in Figs. 4 and A. is a wheel which turns, with friction, upon thepivot G, of the seconds hand 7), and this wheel is in the form of acrown wheel. having sixty ratchet teeth on its upper side. There are twoseconds hands,

E, E, and K, K, which ordinarily stand directly over each other, andappear as one, the lowermost of which E, E, may be stopped at anymoment, whlle the uppermost, K, K, will continue to beat seconds. Thisis effected in the following manner: D, Fig. 5, represents a barrelwhich turns freely upon the pivot C; upon this barrel is aitixed thehand E E, and upon its lower end is also afliXed the spring 1", havingupon its lower side a tooth t, which takes into the ratchet teeth on thewheel A, connecting the barrel 1), with said wheel when the spring isdown, and leaving it free when the spring is raised, as it isrepresented at I, Fig. 5. For the purpose of raising this spring, 1construct a ring B, B, seen flatwise in Fig. 4t, which is attached to anelas tic, or spring, piece G, the ring being so placed that the pivot ofthe seconds hand shall be in its center. The spring piece G, is operatedupon by the latch H, which when in the position shown in Fig. 5, raisesthe ring B, B, and with it the spring 7. When so raised, the hand E isimmediately stopped, while the hand K, which is held upon the upper endof the pivot C, by friction, being forced on in the usual manner,continues its motion, its movement being accompanied by that of thewheel A, but not of the barrel D, which is arrested by the friction ofthe spring 1", upon the ring B, B. The position of the spring 1", whenengaged in the ratchet wheel A, is represented by the letter S, the twohands then moving together.

Time keepers constructed in the manner above described present severalimportant advantages over those of the ordinary construction, as will beat once apparent to those familiar with watch movements. They are lesscomplicated than those ordinarily showing dead seconds, having siXwheels and a main spring less than the latter. They can consequently beafforded at a less price, will be less liable to be out of repair, andbe more easily kept in order. As a stop watch, for the purpose of makingaccurate observations its special utility will be evident; the arrestingof the lower hand, and the continued motion of the upper, causing thelatter to count the seconds with the utmost precision, the lower alwaysindicating the point of departure of the upper hand.

Having thus fully described all those parts of a time keeper which arenecessary to enable a competent workman to carry the same intooperation, I hereby declare that what I claim as my invention, anddesire to secure by Letters Patent, consists- 1. In constructing theescapement wheel R, with bifurcated teeth, so that in op-erat ing on therouleau placed on the pivot of the balance wheel a greater number ofvibrations may be produced than in ordinary duplex watches; and inmaking it without the pinion hitherto placed on its axis, (which in myarrangement is transferred to the wheel G.) by means of which improvedconstruction of the escapement wheel its pressure on the rouleau islessened, as above described.

2. I also claim the combining therewith the wheel G, with its pinion G,for the purpose and in the manner set forth.

3. In the seconds part I claim the manner of combining and arranging thedouble hands, the barrel D, the ratchet spring 1, and the ratchet wheel,to be operated upon by means of the ring and latch, in the manner, andfor the purpose described.

EDWARD JACOT DES COMBES.

Witnesses JOHN E. RIGDENs, A. LEooUR.

